A door cutting guide used in conjunction with a saw to cut a door has a slot in it in which the blade of a saw travels and includes surfaces on the guide which interact with the baseplate of the saw in making a straight cut through the door. The door cutting guide is useful in sawing off the bottoms of doors allowing them to freely open and close across rugs or other raised surfaces.
In constructing new structures it is the practice to hang or suspend standard size doors within standard size frames. When the interior decoration of the structure is decided upon, the floor surface of the rooms which the door separates may be covered with a fairly thin material such as a linoleum or a tile, or may be covered with thicker material such as a carpet and its accompanying carpet pad. In order to accommodate the floor covering it may be necessary to cut off the bottom of the door to allow the door to freely open and close without binding against the floor covering.
It used to be standard construction practice to carefully size a door prior to installing it. Because of rising construction costs it is no longer economically feasible to invest the hand labor necessary to custom fit each and every door. For this reason standard size doors and door fittings are used. Once the door is hung, and it is determined that there is insufficient clearance between the bottom of the door and the floor to allow free movement of the door across the floor covering, one of several methods are presently practiced in cutting off the bottom of the door. The first of these would be to remove the door, mark it, and then cut it either freehand or using a strip of wood clamped to the door as a saw guide. The second method is to use the floor as a guide for the baseplate of a circular saw and attempt to cut off the door while it is hanging.
The first method described in the preceding paragraph is disadvantageous because of the expensive labor time it consumes in removing and rehanging the door. The second method is disadvantageous for several reasons. The first of these is that typically cement slab floors or other subfloors are not smooth and level. When a saw is slid across the cement slab or the subfloor any discontinuities or imperfections in its surface are transferred to the saw resulting in either an uneven cut of the door or binding of the saw blade. The second disadvantage of this method is that very few hand-held circular saws are adjustable with respect to the distance of the blade from the edge of the baseplate. Thus, the carpenter has no control over how high the door will be cut off with respect to the floor, but is limited to the particular dimensions achieved in using his saw based on the dimension of the saw blade from the edge of the baseplate. Saw guides or jigs are known which can be used with hand-held circular saws. However, no guides or jigs are known which can be used in cutting off the bottom of a door while the door is hanging.
Further, the known jigs either rely on gravity to retain them in position on a horizontal surface or they must be clamped to the surface of the wood which is being cut if the surface is not horizontal. This, then renders these jigs and guides unusable for vertical surfaces unless clamps are used. Clamps, however, require expenditure of labor time in both mounting and dismounting them and they can mar the surfaces of the door. Further, they can get in the way of the saw which can be dangerous for the operator of the saw.
U.S. Pat. No. 2,614,591 describes an attachment for a plane which allows the door to be planed while it is in a hanging position. However, as anyone skilled with working with wood knows, planing is a very slow technique and as such would never be used by the building industry because of the high labor costs associated with it.